/*  cram.h -- public CRAM-specific API functions.

    Copyright (C) 2015 Genome Research Ltd.

    Author: James Bonfield <jkb@sanger.ac.uk>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.  */

/*! \file
 * CRAM interface.
 *
 * Consider using the higher level hts_*() API for programs that wish to
 * be file format agnostic (see htslib/hts.h).
 *
 * This API should be used for CRAM specific code. The specifics of the
 * public API are implemented in cram_io.h, cram_encode.h and cram_decode.h
 * although these should not be included directly (use this file instead).
 */

#ifndef HTSLIB_CRAM_H
#define HTSLIB_CRAM_H

#include <stdarg.h>
#include <stdint.h>
#include <sys/types.h>

#include "hts.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifndef _CRAM_STRUCTS_H_
enum cram_block_method {
    ERROR    = -1,
    RAW      = 0,
    GZIP     = 1,
    BZIP2    = 2,
    LZMA     = 3,
    RANS     = 4,  // Generic; either order
    RANS0    = 4,
    RANS1    = 10, // Not externalised; stored as RANS (generic)
    GZIP_RLE = 11, // NB: not externalised in CRAM
};

enum cram_content_type {
    CT_ERROR           = -1,
    FILE_HEADER        = 0,
    COMPRESSION_HEADER = 1,
    MAPPED_SLICE       = 2,
    UNMAPPED_SLICE     = 3, // CRAM V1.0 only
    EXTERNAL           = 4,
    CORE               = 5,
};

// Opaque data types, see cram_structs for the fully fledged versions.
typedef struct SAM_hdr SAM_hdr;
typedef struct cram_file_def cram_file_def;
typedef struct cram_fd cram_fd;
typedef struct cram_container cram_container;
typedef struct cram_block cram_block;
typedef struct cram_slice cram_slice;
typedef struct cram_metrics cram_metrics;
typedef struct cram_block_slice_hdr cram_block_slice_hdr;
typedef struct cram_block_compression_hdr cram_block_compression_hdr;
typedef struct refs_t refs_t; // need this?

struct hFILE;
#endif

// Accessor functions

/*
 *-----------------------------------------------------------------------------
 * cram_fd
 */
SAM_hdr *cram_fd_get_header(cram_fd *fd);
void cram_fd_set_header(cram_fd *fd, SAM_hdr *hdr);

int cram_fd_get_version(cram_fd *fd);
void cram_fd_set_version(cram_fd *fd, int vers);

int cram_major_vers(cram_fd *fd);
int cram_minor_vers(cram_fd *fd);

struct hFILE *cram_fd_get_fp(cram_fd *fd);
void cram_fd_set_fp(cram_fd *fd, struct hFILE *fp);


/*
 *-----------------------------------------------------------------------------
 * cram_container
 */
int32_t cram_container_get_length(cram_container *c);
void cram_container_set_length(cram_container *c, int32_t length);
int32_t cram_container_get_num_blocks(cram_container *c);
void cram_container_set_num_blocks(cram_container *c, int32_t num_blocks);
int32_t *cram_container_get_landmarks(cram_container *c, int32_t *num_landmarks);
void cram_container_set_landmarks(cram_container *c, int32_t num_landmarks,
                                  int32_t *landmarks);

/* Returns true if the container is empty (EOF marker) */
int cram_container_is_empty(cram_fd *fd);


/*
 *-----------------------------------------------------------------------------
 * cram_block
 */
int32_t cram_block_get_content_id(cram_block *b);
int32_t cram_block_get_comp_size(cram_block *b);
int32_t cram_block_get_uncomp_size(cram_block *b);
int32_t cram_block_get_crc32(cram_block *b);
void *  cram_block_get_data(cram_block *b);

enum cram_content_type cram_block_get_content_type(cram_block *b);

void cram_block_set_content_id(cram_block *b, int32_t id);
void cram_block_set_comp_size(cram_block *b, int32_t size);
void cram_block_set_uncomp_size(cram_block *b, int32_t size);
void cram_block_set_crc32(cram_block *b, int32_t crc);
void cram_block_set_data(cram_block *b, void *data);

int cram_block_append(cram_block *b, void *data, int size);
void cram_block_update_size(cram_block *b);

// Offset is known as "size" internally, but it can be confusing.
size_t cram_block_get_offset(cram_block *b);
void cram_block_set_offset(cram_block *b, size_t offset);

/*
 * Computes the size of a cram block, including the block
 * header itself.
 */
uint32_t cram_block_size(cram_block *b);

/*
 * Renumbers RG numbers in a cram compression header.
 *
 * CRAM stores RG as the Nth number in the header, rather than a
 * string holding the ID: tag.  This is smaller in space, but means
 * "samtools cat" to join files together that contain single but
 * different RG lines needs a way of renumbering them.
 *
 * The file descriptor is expected to be immediately after the
 * cram_container structure (ie before the cram compression header).
 * Due to the nature of the CRAM format, this needs to read and write
 * the blocks itself.  Note that there may be multiple slices within
 * the container, meaning multiple compression headers to manipulate.
 * Changing RG may change the size of the compression header and
 * therefore the length field in the container.  Hence we rewrite all
 * blocks just incase and also emit the adjusted container.
 *
 * The current implementation can only cope with renumbering a single
 * RG (and only then if it is using HUFFMAN or BETA codecs).  In
 * theory it *may* be possible to renumber multiple RGs if they use
 * HUFFMAN to the CORE block or use an external block unshared by any
 * other data series.  So we have an API that can be upgraded to
 * support this, but do not implement it for now.  An example
 * implementation of RG as an EXTERNAL block would be to find that
 * block and rewrite it, returning the number of blocks consumed.
 *
 * Returns 0 on success;
 *        -1 if unable to edit;
 *        -2 on other errors (eg I/O).
 */
int cram_transcode_rg(cram_fd *in, cram_fd *out,
                      cram_container *c,
                      int nrg, int *in_rg, int *out_rg);

/*
 * Copies the blocks representing the next num_slice slices from a
 * container from 'in' to 'out'.  It is expected that the file pointer
 * is just after the read of the cram_container and cram compression
 * header.
 *
 * Returns 0 on success
 *        -1 on failure
 */
int cram_copy_slice(cram_fd *in, cram_fd *out, int32_t num_slice);

/*
 *-----------------------------------------------------------------------------
 * SAM_hdr
 */

/*! Tokenises a SAM header into a hash table.
 *
 * Also extracts a few bits on specific data types, such as @RG lines.
 *
 * @return
 * Returns a SAM_hdr struct on success (free with sam_hdr_free());
 *         NULL on failure
 */
SAM_hdr *sam_hdr_parse_(const char *hdr, int len);


/*
 *-----------------------------------------------------------------------------
 * cram_io basics
 */

/**@{ ----------------------------------------------------------------------
 * CRAM blocks - the dynamically growable data block. We have code to
 * create, update, (un)compress and read/write.
 *
 * These are derived from the deflate_interlaced.c blocks, but with the
 * CRAM extension of content types and IDs.
 */

/*! Allocates a new cram_block structure with a specified content_type and
 * id.
 *
 * @return
 * Returns block pointer on success;
 *         NULL on failure
 */
cram_block *cram_new_block(enum cram_content_type content_type,
                           int content_id);

/*! Reads a block from a cram file.
 *
 * @return
 * Returns cram_block pointer on success;
 *         NULL on failure
 */
cram_block *cram_read_block(cram_fd *fd);

/*! Writes a CRAM block.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_write_block(cram_fd *fd, cram_block *b);

/*! Frees a CRAM block, deallocating internal data too.
 */
void cram_free_block(cram_block *b);

/*! Uncompresses a CRAM block, if compressed.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_uncompress_block(cram_block *b);

/*! Compresses a block.
 *
 * Compresses a block using one of two different zlib strategies. If we only
 * want one choice set strat2 to be -1.
 *
 * The logic here is that sometimes Z_RLE does a better job than Z_FILTERED
 * or Z_DEFAULT_STRATEGY on quality data. If so, we'd rather use it as it is
 * significantly faster.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_compress_block(cram_fd *fd, cram_block *b, cram_metrics *metrics,
                        int method, int level);

/**@}*/
/**@{ ----------------------------------------------------------------------
 * Containers
 */

/*! Creates a new container, specifying the maximum number of slices
 * and records permitted.
 *
 * @return
 * Returns cram_container ptr on success;
 *         NULL on failure
 */
cram_container *cram_new_container(int nrec, int nslice);
void cram_free_container(cram_container *c);

/*! Reads a container header.
 *
 * @return
 * Returns cram_container on success;
 *         NULL on failure or no container left (fd->err == 0).
 */
cram_container *cram_read_container(cram_fd *fd);

/*! Writes a container structure.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_write_container(cram_fd *fd, cram_container *h);

/*
 * Stores the container structure in dat and returns *size as the
 * number of bytes written to dat[].  The input size of dat is also
 * held in *size and should be initialised to cram_container_size(c).
 *
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_store_container(cram_fd *fd, cram_container *c, char *dat, int *size);

int cram_container_size(cram_container *c);

/**@}*/
/**@{ ----------------------------------------------------------------------
 * The top-level cram opening, closing and option handling
 */

/*! Opens a CRAM file for read (mode "rb") or write ("wb").
 *
 * The filename may be "-" to indicate stdin or stdout.
 *
 * @return
 * Returns file handle on success;
 *         NULL on failure.
 */
cram_fd *cram_open(const char *filename, const char *mode);

/*! Opens an existing stream for reading or writing.
 *
 * @return
 * Returns file handle on success;
 *         NULL on failure.
 */
cram_fd *cram_dopen(struct hFILE *fp, const char *filename, const char *mode);

/*! Closes a CRAM file.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_close(cram_fd *fd);

/*
 * Seek within a CRAM file.
 *
 * Returns 0 on success
 *        -1 on failure
 */
int cram_seek(cram_fd *fd, off_t offset, int whence);

/*
 * Flushes a CRAM file.
 * Useful for when writing to stdout without wishing to close the stream.
 *
 * Returns 0 on success
 *        -1 on failure
 */
int cram_flush(cram_fd *fd);

/*! Checks for end of file on a cram_fd stream.
 *
 * @return
 * Returns 0 if not at end of file
 *         1 if we hit an expected EOF (end of range or EOF block)
 *         2 for other EOF (end of stream without EOF block)
 */
int cram_eof(cram_fd *fd);

/*! Sets options on the cram_fd.
 *
 * See CRAM_OPT_* definitions in hts.h.
 * Use this immediately after opening.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_set_option(cram_fd *fd, enum hts_fmt_option opt, ...);

/*! Sets options on the cram_fd.
 *
 * See CRAM_OPT_* definitions in hts.h.
 * Use this immediately after opening.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_set_voption(cram_fd *fd, enum hts_fmt_option opt, va_list args);

/*!
 * Attaches a header to a cram_fd.
 *
 * This should be used when creating a new cram_fd for writing where
 * we have an SAM_hdr already constructed (eg from a file we've read
 * in).
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int cram_set_header(cram_fd *fd, SAM_hdr *hdr);


/* As int32_decoded/encode, but from/to blocks instead of cram_fd */
int int32_put_blk(cram_block *b, int32_t val);

/**@}*/
/**@{ -------------------------------------------------------------------*/
/*! Deallocates all storage used by a SAM_hdr struct.
 *
 * This also decrements the header reference count. If after decrementing
 * it is still non-zero then the header is assumed to be in use by another
 * caller and the free is not done.
 *
 * This is a synonym for sam_hdr_dec_ref().
 */
void sam_hdr_free(SAM_hdr *hdr);

/*! Returns the current length of the SAM_hdr in text form.
 *
 * Call sam_hdr_rebuild() first if editing has taken place.
 */
int sam_hdr_length(SAM_hdr *hdr);

/*! Returns the string form of the SAM_hdr.
 *
 * Call sam_hdr_rebuild() first if editing has taken place.
 */
char *sam_hdr_str(SAM_hdr *hdr);

/*! Appends a formatted line to an existing SAM header.
 *
 * Line is a full SAM header record, eg "@SQ\tSN:foo\tLN:100", with
 * optional new-line. If it contains more than 1 line then multiple lines
 * will be added in order.
 *
 * Len is the length of the text data, or 0 if unknown (in which case
 * it should be null terminated).
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */

/*! Add an @PG line.
 *
 * If we wish complete control over this use sam_hdr_add() directly. This
 * function uses that, but attempts to do a lot of tedious house work for
 * you too.
 *
 * - It will generate a suitable ID if the supplied one clashes.
 * - It will generate multiple @PG records if we have multiple PG chains.
 *
 * Call it as per sam_hdr_add() with a series of key,value pairs ending
 * in NULL.
 *
 * @return
 * Returns 0 on success;
 *        -1 on failure
 */
int sam_hdr_add_PG(SAM_hdr *sh, const char *name, ...);

/*!
 * A function to help with construction of CL tags in @PG records.
 * Takes an argc, argv pair and returns a single space-separated string.
 * This string should be deallocated by the calling function.
 *
 * @return
 * Returns malloced char * on success;
 *         NULL on failure
 */
char *stringify_argv(int argc, char *argv[]);
/**@}*/

#ifdef __cplusplus
}
#endif

#endif
